summaryrefslogtreecommitdiff
path: root/include/asm-v850/delay.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-v850/delay.h')
-rw-r--r--include/asm-v850/delay.h47
1 files changed, 47 insertions, 0 deletions
diff --git a/include/asm-v850/delay.h b/include/asm-v850/delay.h
new file mode 100644
index 000000000000..1ce65d48a7c5
--- /dev/null
+++ b/include/asm-v850/delay.h
@@ -0,0 +1,47 @@
+/*
+ * include/asm-v850/delay.h -- Delay routines, using a pre-computed
+ * "loops_per_second" value
+ *
+ * Copyright (C) 2001,03 NEC Corporation
+ * Copyright (C) 2001,03 Miles Bader <miles@gnu.org>
+ * Copyright (C) 1994 Hamish Macdonald
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ */
+
+#ifndef __V850_DELAY_H__
+#define __V850_DELAY_H__
+
+#include <asm/param.h>
+
+extern __inline__ void __delay(unsigned long loops)
+{
+ if (loops)
+ __asm__ __volatile__ ("1: add -1, %0; bnz 1b"
+ : "=r" (loops) : "0" (loops));
+}
+
+/*
+ * Use only for very small delays ( < 1 msec). Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays. This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+
+extern unsigned long loops_per_jiffy;
+
+extern __inline__ void udelay(unsigned long usecs)
+{
+ register unsigned long full_loops, part_loops;
+
+ full_loops = ((usecs * HZ) / 1000000) * loops_per_jiffy;
+ usecs %= (1000000 / HZ);
+ part_loops = (usecs * HZ * loops_per_jiffy) / 1000000;
+
+ __delay(full_loops + part_loops);
+}
+
+#endif /* __V850_DELAY_H__ */